451  Man needs his difficulties because they are necessary to enjoy success,
626  If I am not for myself, who is for me?And being for my own self, what am 'I'? And if not now, when?
511  We are in the habit of exaggerating or imagining or anticipating sorrow. We are torn by things present or about things yet to come. Consider whether your proofs of future troubles are sure. For it is more often the case that we are troubled by our apprehensions.
645  There are more things..likely to frighten us, than to crush us.We suffer more in the imagination than in reality.
552  "Be the change you want to see in this world."